Magnesium base alloy



Solution heat treated alloys MAGNESIUM BASE ALLOY John A. Gann, Midland, Mich., 'assgno to The 3 Claims- (Cl. l5-168) The present invention relates to magnesium alloy Pfentea July ze, 193s UNITED STATES PATENT OFFICE Dow Chemical Company, Midland, Mich., a corporation of Michigan No Drawing. Application August 2, 1937, Serial s and more particularly to those in which The establishment of the percentage of each metal in these new alloys depends on the use for which the material is intended. In general, I prefer to use alloys containing more than per cent of magnesium and less than 20 per cent of total added metals, but where the material is to be used for the production of Wrought shapes, the alloy is lusually restricted to compositions containing more than per cent of magnesium and less than 10 per cent of total added metals. For the production of castings, the alloy should preferably contain approximately 85 to 92 per cent of magnesium, 4 to 10 per cent of aluminum, 1 to 5 per cent of cadmium, 0.1 to 0.3 per cent'of manganese, 1 to 8 per cent of lead, and 1 to 6 per cent of tin. Where zinc is likewise required it should be present in amounts ranging from about 2 to 4 per cent. For the production of wrought shapes by extrusion and forging, the alloys should, in general, contain these metals in the following proportions: 1 to 8 per cent of aluminum, 0.5 to 3 per cent of cadmium, 0.1 to 0.5 per cent ofmanganese, 0.5 to 2 per cent of lead,

0.5 to 3 per cent of tin, and 0.5 to 2 per cent ofI zinc. If the alloy is to be fabricated byK rolling rather than by extrusion or forging, the percentage of aluminum should preferably lie within the range of 1 to 5 per cent.

My new polynary alloys may be prepared by the methods usually employed for melting and alloylng metals with magnesium, such as adding the respective alloying metals singly or jointly to a bath of molten magnesium protected from oxidationby a covei of fluid ux. The solution heat treatment for the zinc-free alloys may consist in heating the material -for 20 hours at 430 C. followed by air cooling, or, when zinc is present Y in the alloy, 12 hours at 320 C. plus 16 hours at 420 C. followed by air cooling. The aging treatment consists of approximately 16 hours heating at 175 C., subsequent to the above solution heat treatment. Plastic deformation operations, such as extruding, forging, and rolling are best conducted at temperatures between 300 and 400 C.

Other modes of applying the principle of my 10 invention may be employed instead of those explained, change being made as-regards the ingredients and the steps herein disclosed, provided those stated by any of the following claims or their equivalent be employed. '15, I particularly point out and distinctly claim proximately 4 to 10 per cent of aluminum and 25 from about 1 to 5 per cent of cadmium, and from about 0.1 to 0.3 per cent of manganese, and from about 1 to 8 per .cent of lead, and from about 1l to 6 per cent of tin, the balance being magnesium.

3. .A magnesium-base alloy consisting of approximately 8 per cent of aluminum, and 3 per cent of cadmium, and 0.3 per cent of manganese, and 1 per cent of lead, and 2 per cent of tin, the balance being magnesium.

JOHN A. GANN. 

